refactor(frontend) : extract shared components and reduce file sizes

- Extract CustomFieldInputGrid.vue from 6 duplicated template blocks (~70 lines each)
- Extract EntityHistorySection.vue from 3 identical history sections in edit pages
- Extract useDragReorder composable from 4 identical drag-and-drop implementations in StructureNodeEditor (~330 lines → ~30)
- Extract catalogDisplayUtils.ts (resolvePrimaryDocument, resolveSupplierNames, buildSuppliersDisplay)
- Remove redundant computed wrappers (historyEntries, loadingTypes, selectedFiles)
- Remove unused imports (fieldKey, historyActionLabel, formatHistoryDate, *HistoryEntry types)
- Move Intl.DateTimeFormat to module-level in date.ts

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/pages/component-catalog.vue

@@ -126,8 +126,9 @@ import { useComposants } from '~/composables/useComposants'
 import { useComponentTypes } from '~/composables/useComponentTypes'
 import { useDataTable } from '~/composables/useDataTable'
 import DocumentThumbnail from '~/components/DocumentThumbnail.vue'
-import { isImageDocument, isPdfDocument } from '~/utils/documentPreview'
 import { resolveDeleteImpact, buildDeleteMessage } from '~/shared/utils/deleteImpactUtils'
+import { resolvePrimaryDocument, resolvePreviewAlt } from '~/shared/utils/catalogDisplayUtils'
+import { formatFrenchDate } from '~/utils/date'
 
 const { canEdit } = usePermissions()
 const { composants, total, loadComposants, loading: loadingComposants, deleteComposant } = useComposants()
@@ -178,23 +179,6 @@ async function fetchComposants() {
   })
 }
 
-const resolvePrimaryDocument = (component: Record<string, any>) => {
-  const documents = Array.isArray(component?.documents) ? component.documents : []
-  if (!documents.length) return null
-  const normalized = documents.filter((doc: any) => doc && typeof doc === 'object')
-  const withPath = normalized.filter((doc: any) => doc?.fileUrl || doc?.path)
-  const pdf = withPath.find((doc: any) => isPdfDocument(doc))
-  if (pdf) return pdf
-  const image = withPath.find((doc: any) => isImageDocument(doc))
-  if (image) return image
-  return withPath[0] ?? normalized[0] ?? null
-}
-
-const resolvePreviewAlt = (component: Record<string, any>) => {
-  const parts = [component?.name, component?.reference].filter(Boolean)
-  return parts.length ? `Aperçu du document de ${parts.join(' – ')}` : 'Aperçu du document'
-}
-
 const resolveComponentType = (component: Record<string, any>) => {
   if (component?.typeComposant?.name) return component.typeComposant.name
   if (component?.typeComposantLabel) return component.typeComposantLabel
@@ -212,12 +196,7 @@ const handleDeleteComponent = async (component: Record<string, any>) => {
   fetchComposants()
 }
 
-const formatDate = (dateStr: string) => {
-  if (!dateStr) return '—'
-  const date = new Date(dateStr)
-  if (Number.isNaN(date.getTime())) return '—'
-  return new Intl.DateTimeFormat('fr-FR', { day: '2-digit', month: '2-digit', year: 'numeric' }).format(date)
-}
+const formatDate = formatFrenchDate
 
 onMounted(async () => {
   await Promise.all([fetchComposants(), loadComponentTypes()])